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At least 1,207 records · Page 67

Processing ultrasonic inspection data from multiple scan patterns for turbine rotor weld build-up evaluations

The study presents a data processing methodology for weld build-up using multiple scan patterns. To achieve an overall high probability of detection for flaws with different orientations, an inspection procedure with three different scan patterns is proposed. The three scan patterns are radial-tangential longitude wave pattern, axial-radial longitude wave pattern, and tangential shear wave pattern. Scientific fusion of the inspection data is implemented using volume reconstruction techniques. The idea is to perform spatial domain forward data mapping for all sampling points. A conservative scheme is employed to handle the case that multiple sampling points are mapped to one grid location. The scheme assigns the maximum value for the grid location to retain the largest equivalent reflector size for the location. The methodology is demonstrated and validated using a realistic ring of weld build-up. Tungsten balls and bars are embedded to the weld build-up during manufacturing process to represent natural flaws. Flat bottomed holes and side drilled holes are installed as artificial flaws. Automatic flaw identification and extraction are demonstrated. Results indicate the inspection procedure with multiple scan patterns can identify all the artificial and natural flaws.

42 ENGINEERING↗

Apparatus and process of retrofitting a combined cycle power plant

A process for retrofitting an electric power plant that uses two 60 Hertz large frame heavy duty industrial gas turbine engines to drive electric generators and produce electricity, where each of the two industrial engines can produce up to 350 MW of output power. The process replaces the two 350 MW industrial engines with one twin spool industrial gas turbine engine that is capable of producing at least 700 MW of output power. Thus, two prior art industrial engines can be replaced with one industrial engine that can produce power equal to the two prior art industrial engines.

20 FOSSIL-FUELED POWER PLANTS↗

Cost-Disruptive, Low Impact, Modular Form Factor Low-Head Hyropower System

Littoral Power Systems, Inc. (LPS) is writing a new story when it comes to turning the natural power of water into electricity. h-Modulor™ is a new way of designing and building hydropower plants that addresses the crucial issues of cost, environmental impact and regulatory time frames. For decades hydropower developers, owners and operators have struggled to build new or expanded facilities that didn’t cost so much, were friendlier to the environment and didn’t take so much time to license or build. The problem is particularly acute in smaller installations. The burdensome regulatory pathway for projects under 10MW in capacity have eased the licensing requirements for small hydro projects. But in small projects are still very hard, because capital costs are a much larger percentage of the generation revenues than they are in large facilities. There is an acute need for a cost effective solution. Understanding this need and opportunity, LPS conceived a new type of hydropower equipment – a kit of standard, pre-fabricated modular parts for dam safety, power generation, spill control and other hydropower facility functions to be used to build and operate a hydro plant at substantially lower costs than are currently achievable. This system of prefabricated parts also showed promise to reduce environmental impacts, reduce engineering time involved in the licensing process, and possibly provide a new way for regulators to think about licensing that could lead to reduced regulatory timeframes. Because of this invention’s compelling and intriguing promise the Department of Energy’s (DOE) Water Power Technology Office (WPTO) awarded funding to LPS through the Office of Energy Efficiency and Renewable Energy (EERE) to develop this new type of hydropower equipment to meet a levelized cost of energy (LCOE) goal and analyze it for dam safety. LPS teamed with professional engineers, PhDs, and geotechnical consultants from GZA GeoEnvironental, Inc. (GZA), Alden Research Laboratory (Alden), University of Massachusetts – Dartmouth (UMass-D), the National Renewable Energy Laboratory (NREL) and AECOM. In collaboration with the engineers and managers at the WPTO and EERE they matured the concepts through substantial design shifts. The project exceeded the original goals and delivered designs beyond the proof-of-concept stage backed up by thorough professional engineering analysis of stability, seepage, and structural integrity. A full-scale section with seals successfully retained water in full-head leakage tests. Construction plans and professional engineering cost estimates indicated an LCOE half of the original LCOE goal. A system of these modules is now on track to be used in a 4.5 MW commercial installation.

13 HYDRO ENERGY↗

Manipulating the Crystallization Kinetics by Additive Engineering toward High-Efficient Photovoltaic Performance

Additive processing is proven to be an effective method to improve the efficiency and stability of perovskite solar cells; however, its intrinsic role in directing the crystallization pathway and thus morphology formation remains unknown. In situ grazing-incidence wide-angle x-ray scattering (GIWAXS) is applied to study the function of a 1,8-diiodooctane (DIO) additive in manipulating the crystallization behavior of perovskite thin films. It is seen that the DIO additive could induce multi-stage intermediate crystallization phases and increases the activation energy for nucleation and growth, which postpones the perovskite phase transformation time and broadens the transition zone. The elongated crystallization process affords improved perovskite thin film crystallinity and reduces defect density, which enables a longer carrier diffusion length. As a result, improved device efficiency, moisture, and thermal stability can be achieved. The following study provides a new prospective in understanding the additive function in perovskite thin film morphology control from fundamental parameters, indicating the importance of minor processing conditions in global property management toward high device performance.

36 MATERIALS SCIENCE↗

Water‐Assisted Liftoff of Polycrystalline CdS/CdTe Thin Films Using Heterogeneous Interfacial Engineering

Abstract Recent advances in device design and process optimizations have enabled the production of CdTe devices on flexible substrates, but the necessary high‐temperature processing (>450 °C) to recrystallize grains limits the use of alternative lightweight substrates. Here, a new synthesis method is reported to create a freestanding CdS/CdTe film by combining high‐temperature depositions (CdS/CdTe on Si/SiO 2 ) and a simple lift‐off process in a water environment at room temperature. Analysis of the results indicate that the delamination is facilitated by the innate lattice mismatch as well as the presence of an unexpected Te‐rich layer (≈20 nm), which accumulates on the SiO 2 surface. High‐resolution electron microscopy and spectroscopy measurements confirm that the CdS/CdTe film is physically liberated from the substrate without leaving any residue, while also preserving their initial structural and compositional properties.

Magginetti, David J.↗

Hierarchical and scalable integration of nanostructures for energy and environmental applications: a review of processing, devices, and economic analyses

Hierarchical nanostructure, an engineered nanostructure with a higher assembly-level of constituents by low dimensional nano-building blocks, has received extensive attentions in the latest advancements in nanomaterial science and nanotechnology development. The ordered hierarchical nanostructures could offer merits such as more active sites, synergistic properties owing to their geometric complexity and building blocks variation, as well as the resultant multi-functional capabilities. In this review, we specifically focus on the integration approaches that may be feasible for large-scale production and manufacturing of engineered nanomaterials for various industrial applications, and the design criteria of hierarchical nanostructures targeted at various sustainable energy and environmental applications. In addition to chemical synthesis and integration methods, the development and application of hierarchical nanostructures are surveyed in energy conversion, generation, storage, utilization, and sensing devices. Meanwhile, a much-needed survey is also touched upon the techno-economic analyses of engineered nanomaterials, proposing the need of establishing various standard protocols on various factors and parameters that could be envisaged as a guide toward the viable transition to the practices in the future nano-industries.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Bench-Scale Development of a Non-Aqueous Solvent (NAS) CO 2 Capture Process for Coal-Fired Power Plants

The project aimed to advance RTI’s non-aqueous amine solvent technology by improving the solvent to reduce volatility, demonstrating long-term continuous operation at lab- (0.5 liters solvent) and bench-scale (~120 liters solvent), showing low reboiler heat duty measured during bench-scale testing, evaluating degradation products, building a rate-based process model, and evaluating the techno-economic performance of the process. The project team (RTI, SINTEF, Linde Engineering) and the technology performed well in each area of advancement. The modifications incorporated throughout the project enabled the attainment of target absorber and regenerator conditions for the process. Reboiler duties below 2,000 kJ t /kg CO 2 were observed in a bench-scale test unit operated at RTI.

01 COAL, LIGNITE, AND PEAT↗

FY24 Laboratory Directed Research and Development Annual Report

The Laboratory Directed Research and Development (LDRD) program yields foundational scientific research and development (R&D) essential to growing SRNL’s core competencies, in alignment with SRNL’s Strategic Plan to provide long-term benefits to the Department of Energy (DOE), the National Nuclear Security Administration (NNSA), and other customers and stakeholders. Five strategic goals are outlined in SRNL’s strategic plan: 1) Provide applied science and engineering for EM’s active clean-up sites and LM’s post closure management sites 2) Provide science-based solutions for gaps identified in nonproliferation strategic vision and support the government in activities impacting national security 3) Lead Science, Technology & Engineering as the central technical authority for processing tritium loaded reservoirs and support production of plutonium pits 4) Align science and energy security programs by focusing modern modeling, simulation, and data analytics tools on materials engineering and performance applications 5) Build a workforce for the future

Clark, Sue [Savannah River National Laboratory (SR↗

Energize: An Interactive Evaluation Tool for Engaging the General Public with Energy Decision Making - Final Report

The public has an ever-increasing interest in the economic, environmental, and social impacts of global energy production. To support informed decision making, the scientific community has a responsibility to communicate reliable and straight-forward information to the general public, in an engaging way, regarding energy systems and how choices made at different stages of an energy technology life cycle can impact the cost, amount of materials used, and waste produced. Our objective is to enhance public engagement via an interactive electrical energy game (Energ!ze) through which players interact with one another in their quest to develop an electrical energy portfolio that optimizes economic (e.g., company profit), environmental (e.g., reduced CO 2 emissions), and social (e.g., public opinion) impacts. The design and development of Energ!ze was an iterative process involving an interdisciplinary team of engineers, discipline-based scientists, computer scientists, and education experts. The development objectives were two-fold: (1) Accurate and quantifiable modeling of electrical energy systems and (2) Engaging and interactive user interface within the construct of the game narrative. The major game mechanics in the current playable Energ!ze version focus on economic metrics, and the database is scaffolded to add environmental and social metrics for future versions. This report details the outcome of the funding period (Section 2 and 3) and describes the development process, along with recommendations for future development (Section 4).

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

ICME and In-Situ Process Monitoring for Rapid Qualification of Components Made by Laser-based Powder Bed Additive Manufacturing Processes for Nuclear Structural Applications

Additive manufacturing (AM) through selective powder bed melting of successive layers is being considered as disruptive technology for rapid production of low-cost nuclear reactor internal components with complex geometries. However, there is a potential for non-uniform distribution of physical features, such as porosity or microstructural differences, due to variations of temperature across a component build. These heterogeneities make the deployment of traditional material qualification and non-destructive evaluation of AM components difficult. This research project explored the feasibility of using in-situ process monitoring methods and integrated computational materials engineering (ICME) principles as an alternate qualification methodology and approach. This project included six individual tasks: (i) design of artifacts relevant to the nuclear power industry, (ii) evaluation of laser processing and in-situ measurements, (iii) computational modeling, (iv) ex-situ microstructural characterization, (v) evaluation of scaling the methodology for large-scale structures, and (vi) development of a data package to codes and standards organizations. As a part of this research, laser powder bed fusion of metals (316L, Alloy 718, and Ti6Al4V) was explored. This document provides an overview of the research performed over three years and serves as the final U.S. Department of Energy report for this project. In the third year, the project focused on the following activities: (a) in-situ infrared and optical imaging of each layer during processing of representative stainless steel geometries; (b) development of methodologies to analyze the data; and (c) application of ICME methodologies and other experiments to estimate the relevance of defects and microstructure to tensile properties.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

ICME and In-Situ Process Monitoring for Rapid Qualification of Components Made by Laser-based Powder Bed Additive Manufacturing Processes for Nuclear Structural Applications

Additive manufacturing (AM) through selective powder bed melting of successive layers is being considered as disruptive technology for rapid production of low-cost nuclear reactor internal components with complex geometries. However, there is a potential for non-uniform distribution of physical features, such as porosity or microstructural differences, due to variations of temperature across a component build. These heterogeneities make the deployment of traditional material qualification and non-destructive evaluation of AM components difficult. This research project explored the feasibility of using in-situ process monitoring methods and integrated computational materials engineering (ICME) principles as an alternate qualification methodology and approach. This project included six individual tasks: (i) design of artifacts relevant to the nuclear power industry, (ii) evaluation of laser processing and in-situ measurements, (iii) computational modeling, (iv) ex-situ microstructural characterization, (v) evaluation of scaling the methodology for large-scale structures, and (vi) development of a data package to codes and standards organizations. As a part of this research, laser powder bed fusion of metals (316L, Alloy 718, and Ti6Al4V) was explored. This document provides an overview of the research performed over three years and serves as the final U.S. Department of Energy report for this project. In the third year, the project focused on the following activities: (a) in-situ infrared and optical imaging of each layer during processing of representative stainless steel geometries; (b) development of methodologies to analyze the data; and (c) application of ICME methodologies and other experiments to estimate the relevance of defects and microstructure to tensile properties.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

ICME and In-Situ Process Monitoring for Rapid Qualification of Components Made by Laser-based Powder Bed Additive Manufacturing Processes for Nuclear Structural Applications

Additive manufacturing (AM) through selective powder bed melting of successive layers is being considered as disruptive technology for rapid production of low-cost nuclear reactor internal components with complex geometries. However, there is a potential for non-uniform distribution of physical features, such as porosity or microstructural differences, due to variations of temperature across a component build. These heterogeneities make the deployment of traditional material qualification and non-destructive evaluation of AM components difficult. This research project explored the feasibility of using in-situ process monitoring methods and integrated computational materials engineering (ICME) principles as an alternate qualification methodology and approach. This project included six individual tasks: (i) design of artifacts relevant to the nuclear power industry, (ii) evaluation of laser processing and in-situ measurements, (iii) computational modeling, (iv) ex-situ microstructural characterization, (v) evaluation of scaling the methodology for large-scale structures, and (vi) development of a data package to codes and standards organizations. As a part of this research, laser powder bed fusion of metals (316L, Alloy 718, and Ti6Al4V) was explored. This document provides an overview of the research performed over three years and serves as the final U.S. Department of Energy report for this project. In the third year, the project focused on the following activities: (a) in-situ infrared and optical imaging of each layer during processing of representative stainless steel geometries; (b) development of methodologies to analyze the data; and (c) application of ICME methodologies and other experiments to estimate the relevance of defects and microstructure to tensile properties.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

ICME and In-Situ Process Monitoring for Rapid Qualification of Components Made by Laser-based Powder Bed Additive Manufacturing Processes for Nuclear Structural Applications

Additive manufacturing (AM) through selective powder bed melting of successive layers is being considered as disruptive technology for rapid production of low-cost nuclear reactor internal components with complex geometries. However, there is a potential for non-uniform distribution of physical features, such as porosity or microstructural differences, due to variations of temperature across a component build. These heterogenities make the deployment of traditional material qualification and non-destructive evaluation of AM components difficult. This research project explored the feasibility of using in-situ process monitoring methods and integrated computational materials engineering (ICME) principles as an alternate qualification methodology and approach. This project included six individual tasks: (i) design of artifacts relevant to the nuclear power industry, (ii) evaluation of laser processing and in-situ measurements, (iii) computational modeling, (iv) ex-situ microstructural characterization, (v) evaluation of scaling the methodology for large-scale structures, and (vi) development of a data package to codes and standards organizations. As a part of this research, laser powder bed fusion of metals (316L, Alloy 718, and Ti6Al4V) was explored. This document provides an overview of the research performed over three years and serves as the final U.S. Department of Energy report for this project. In the third year, the project focused on the following activities: (a) in-situ infrared and optical imaging of each layer during processing of representative stainless steel geometries; (b) development of methodologies to analyze the data; and (c) application of ICME methodologies and other experiments to estimate the relevance of defects and microstructure to tensile properties.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

ICME and In-Situ Process Monitoring for Rapid Qualification of Components Made by Laser-based Powder Bed Additive Manufacturing Processes for Nuclear Structural Applications

Additive manufacturing (AM) through selective powder bed melting of successive layers is being considered as disruptive technology for rapid production of low-cost nuclear reactor internal components with complex geometries. However, there is a potential for non-uniform distribution of physical features, such as porosity or microstructural differences, due to variations of temperature across a component build. These heterogenities make the deployment of traditional material qualification and non-destructive evaluation of AM components difficult. This research project explored the feasibility of using in-situ process monitoring methods and integrated computational materials engineering (ICME) principles as an alternate qualification methodology and approach. This project included six individual tasks: (i) design of artifacts relevant to the nuclear power industry, (ii) evaluation of laser processing and in-situ measurements, (iii) computational modeling, (iv) ex-situ microstructural characterization, (v) evaluation of scaling the methodology for large-scale structures, and (vi) development of a data package to codes and standards organizations. As a part of this research, laser powder bed fusion of metals (316L, Alloy 718, and Ti6Al4V) was explored. This document provides an overview of the research performed over three years and serves as the final U.S. Department of Energy report for this project. In the third year, the project focused on the following activities: (a) in-situ infrared and optical imaging of each layer during processing of representative stainless steel geometries; (b) development of methodologies to analyze the data; and (c) application of ICME methodologies and other experiments to estimate the relevance of defects and microstructure to tensile properties.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Passive SCR Performance Under Pseudo-Transient Cycle: Challenges and Opportunities for Meeting Tier 3 Emissions

We report that the passive ammonia (NH 3 ) selective catalytic reduction (SCR) system is a potential approach for controlling nitrogen oxide (NOx) emissions from lean-burn gasoline engines based on utilizing NH 3 generated by a three-way catalyst (TWC) during brief periods of fuel-rich engine operation. NH 3 generated by the TWC is stored and available to reduce NOx on a downstream SCR catalyst during subsequent periods of lean engine operation. Control of the overall passive SCR process can be more challenging than current urea-based approach because it depends explicitly on fuel-rich engine operation, which must be implemented in the context of transient engine operation. Under transient engine operation, significant variation in SCR temperatures is also to be expected. With NH 3 storage capacity highly dependent on exhaust temperatures, proper system architecture and engine operating strategy are needed for effective NH 3 utilization over the SCR catalyst. In this study, the performance of a passive SCR system was evaluated on a 2.0-l BMW lean-burn gasoline direct injection engine under 6-mode pseudo-transient cycle. The aim of this work is to understand how various engine operating strategies change the dynamics of NH 3 generation and utilization, and NOx reduction in the passive SCR system. A 5.9% fuel economy improvement relative to stoichiometric-only operation with 0.018 g/mi of NOx + NMHC emissions were demonstrated over 6-mode pseudo-transient cycle; however, CO emissions were twice the emission standard. In conclusion, the results of this work reveal challenges and opportunities for meeting Tier 3 emissions and improving fuel savings benefits.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Characterization of Saltstone Grout Line Samples

During a prestart recirculation operation in the Saltstone Processing Facility (SPF), operations staff noticed hardened scaling falling into the hopper. As a result, SPF operators and Saltstone Engineering decided to postpone operation and conduct a process room hopper cleanout. During the cleanout effort personnel noted greater than normal buildup of damp solid material in the transfer line. A borescope investigation was conducted and confirmed buildup was present throughout the transfer line to the downstream valves. Savannah River National Laboratory personnel were asked to characterize the scale material and samples collected from the saltstone grout line and provide recommendations and/or further guidance as to whether additional corrosion testing is needed for useful equipment operating life information. Based on the samples characterized results, the plug material contained only the 60:40 slag:fly ash saltstone. Portland cement in the original 10:45:45 Portland cement:slag:fly ash mix may result in a less abrasive slurry compared to the 60:40 slag:fly ash mix because the slag is > 95 % crushed angular, sharp edged glass. Saltstone grout erosion and corrosion testing of A36 carbon steel is needed to determine if the 60:40 mix is more abrasive and corrosive for A36 carbon steel than the 10:45:45 mix.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Integration of a Wigner effect-based energy storage system with an advanced nuclear reactor

In this work, an innovative energy storage concept based on the purposeful creation of defects in crystalline material by neutron irradiation is presented. Lattice defects are generated when heavy particles collide with the atoms in a crystal structure, i.e., if the incoming particles have enough energy, recoil atoms are displaced from their initial lattice sites. Most of the displaced atoms will eventually combine with nearby vacancies, but some of them will come to rest in non-ideal locations. The energy held by displaced atoms is called Wigner energy. Lattice defects can migrate and form clusters, and the Wigner energy can be released from these groupings if sufficient activation energy is provided. In the nuclear industry, this effect is well-known since it represented an issue for graphite-moderated reactors. This work presents the conceptual design of an engineering system that exploits this physical process to store the energy of neutrons in advanced reactor concepts. In the first part of the paper, the theoretical performance of an energy storage system based on the Wigner effect is described. Given the lattice properties and the compatibility with the harsh reactor environment, graphite was selected as the candidate material for the irradiation targets. Both experimental data and molecular dynamics simulations confirmed that this system can achieve performance comparable with state-of-the-art batteries in terms of stored energy density. In the second part of the paper, the engineering challenges of this innovative technology and the proposed solutions are described. After defining the optimal irradiation conditions, the different steps of the operation of the proposed energy system (from energy storing to energy harvesting) were defined. Finally, the integration of this concept with advanced reactor designs, i.e., a Sodium-cooled Fast Reactor and a Molten Salt-cooled Reactor, was investigated and the corresponding performance was evaluated.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Constructing a Simulation Surrogate with Partially Observed Output

Gaussian process surrogates are a popular alternative to directly using computationally expensive simulation models. When the simulation output consists of many responses, dimension-reduction techniques are often employed to construct these surrogates. However, surrogate methods with dimension reduction generally rely on complete output training data. This article proposes a new Gaussian process surrogate method that permits the use of partially observed output while remaining computationally efficient. The new method involves the imputation of missing values and the adjustment of the covariance matrix used for Gaussian process inference. The resulting surrogate represents the available responses, disregards the missing responses, and provides meaningful uncertainty quantification. In conclusion, the proposed approach is shown to offer sharper inference than alternatives in a simulation study and a case study where an energy density functional model that frequently returns incomplete output is calibrated.

42 ENGINEERING↗